1998 TOYOTA LAND CRUISER spark plugs

A21429
ECM
No.1 Ignition Coil with Igniter
No. 2 Ignition
Coil with Igniter Crankshaft
Position
Sensor
Camshaft
Position
Sensor
Other Sensors:
No. 3 Ignition
Coil with Igniter
No. 4 Ignition
Coil with Igniter
No. 5 Ignition
Coil with Igniter
No. 6 Ignition
Coil with Igniter
No. 7 Ignition
Coil with Igniter
No. 8 Ignition
Coil with Igniter
TA C
To TachometerFrom Battery
Igniter
Ignition CoilSpark Plug
No. 1 Cylinder
No. 4 Cylinder
No. 5 Cylinder
No. 6 Cylinder No. 2 Cylinder
No. 3 Cylinder
No. 7 Cylinder
No. 8 Cylinder IGT1
IGF1
IGT2
IGF2
IGT3
IGT4
IGT5
IGT6
IGT7
IGT8 (Engine Coolant Temp.
Sensor, Mass Air Flow
Sensor, Throttle Position
Sensor, etc.)
- DIAGNOSTICSENGINE
DI-203
396 Author
: Date
:
2004 LAND CRUISER (RM1071U)
CIRCUIT DESCRIPTION
These DTCs indicate a malfunction related to primary circuit.
The DIS is a 1-cylinder ignition system which ignites one cylinder with one ignition coil. In the 1-cylinder
ignition system, the one spark plug is connected to the end of the secondary winding. High voltage generated
in the secondary winding is applied directly to the spark plug. The spark of the spark plug passes from the
center electrode to the ground electrode.
The ECM determines the ignition timing and outputs the ignition signals (IGTs) for each cylinder. Using the
IGT, the ECM turns on and off the power transistor inside the igniter and this switches on and off the current
to the primary coil. When current to the primary coil is cut off, high-voltage is generated in the secondary
coil and this voltage is applied to the spark plugs to create sparks inside the cylinders. As the ECM cuts the
current to the primary coil, the igniter sends back the ignition confirmation signal (IGF) for each cylinder igni-
tion to the ECM.

EM0KR-09
A04458
Compression
Gauge
- ENGINE MECHANICALCOMPRESSION
EM-3
1576 Author
: Date
:
2004 LAND CRUISER (RM1071U)
COMPRESSION
INSPECTION
HINT:
If there is a lack of power, excessive oil consumption or poor fuel
economy, measure the compression pressure.
1. WARM UP AND STOP ENGINE
Allow the engine to warm up to the normal operating tempera-
ture.
2. REMOVE SPARK PLUGS
(See page IG-1)
3. CHECK CYLINDER COMPRESSION PRESSURE
(a) Insert a compression gauge into the spark plug hole.
(b) Fully open the throttle.
(c) While cranking the engine, measure the compression
pressure.
HINT:
Always use a fully charged battery to obtain the engine speed
at 250 rpm or more.
(d) Repeat steps (a) to (c) for each cylinder.
NOTICE:
This measurement must be done as quickly as possible.
Compression pressure:
1,324 kPa (13.5 kgf/cm
2, 192 psi) or more
Minimum pressure:
981 kPa (10.0 kgf/cm
2, 142 psi)
Difference between each cylinder:
98 kPa (1.0 kgf/cm
2, 14 psi) or less
(e) If the cylinder compression in one or more cylinders is
lower than the specification, pour a small amount of en-
gine oil into the cylinder through the spark plug hole and
repeat steps (a) to (c) for the cylinders.

If adding oil helps the compression, chances are
that the piston rings and/or cylinder bore are worn
or damage.

If the pressure stays low, a valve may be sticking or
the seating is improper, or there may be leakage
past the gasket.
4. REINSTALL SPARK PLUGS
(See page IG-1)

A04473
RH Cylinder Head
LH Cylinder HeadA
A
A11159
Painted Mark90°
180°
A02888
A02861
- ENGINE MECHANICALCYLINDER HEAD
EM-61
1634 Author
: Date
:
2004 LAND CRUISER (RM1071U)
NOTICE:
Do not drop the plate washer of the cylinder head bolt into
A area in the illustration. It will fall down to the oil pan
through the cylinder head and the cylinder block.
(d) Mark the front of the cylinder head bolt head with paint.
(e) Retighten the cylinder head bolts by 90° only for the first
time.
(f) Then retighten them by 90° further for the second time.
(g) Check that the painted mark is now at a 180° angle to the
front.
5. INSTALL SPARK PLUGS
6. ASSEMBLE EXHAUST CAMSHAFT
(a) Install the camshaft gear spring, the camshaft sub-gear
and the wave washer.
HINT:
Attach the pins on the gears to the gear spring ends.
(b) Using snap ring pliers, install the snap ring.

A02861
A04471
Oil Seal
A04472
RH Cylinder Head
LH Cylinder HeadFront
19
108
76
5
4
32
1
351082
4697
- ENGINE MECHANICALCYLINDER HEAD
EM-41
1614 Author
: Date
:
2004 LAND CRUISER (RM1071U)
(c) Using snap ring pliers, remove the snap ring.
(d) Remove the wave washer.
(e) Remove the camshaft sub-gear.
(f) Remove the camshaft gear spring.
HINT:
Arrange the camshaft sub-gears and gear spring (RH and LH
sides).
NOTICE:
Be careful not to damage the camshaft timing tube.
23. REMOVE OIL SEAL FROM INTAKE CAMSHAFT
24. REMOVE SPARK PLUGS
25. REMOVE CYLINDER HEAD AND EXHAUST MAN-
IFOLD ASSEMBLIES
(a) Uniformly loosen the 10 cylinder head bolts on one side
of each cylinder head in a little at a time for several times
as in the sequence shown, then do the other side as
shown. Remove the 20 cylinder head bolts and the plate
washers.
NOTICE:

Removing the bolts in incorrect order could cause a
warp or cracks in the cylinder head.

2004 LAND CRUISER (EWD548U)
18E GLOSSARY OF TERMS AND SYMBOLS
BATTERY
Stores chemical energy and
converts it into electrical energy.
Provides DC current for the auto's
various electrical circuits.GROUND
The point at which wiring attaches to
the Body, thereby providing a return
path for an electrical circuit; without a
ground, current cannot flow.
CAPACITOR (Condenser)
A small holding unit for temporary
storage of electrical voltage.HEADLIGHTS
Current flow causes a headlight
filament to heat up and emit light. A
headlight may have either a single
(1) filament or a double (2) filament
1. SINGLE
FILAMENT
CIGARETTE LIGHTER
An electric resistance heating
element.2. DOUBLE
FILAMENT
CIRCUIT BREAKER
Basically a reusable fuse, a circuit
breaker will heat and open if too
much current flows through it.
Some units automatically reset when
cool, others must be manually reset.HORN
An electric device which sounds a
loud audible signal.
DIODE
A semiconductor which allows
current flow in only one direction.IGNITION COIL
Converts low-voltage DC current
into high-voltage ignition current for
firing the spark plugs.
DIODE, ZENERA diode which allows current flow in one
direction but blocks reverse flow only up
to a specific voltage. Above that potential,
it passes the excess voltage. This acts as
a simple voltage regulator.LIGHT
Current flow through a filament
causes the filament to heat up and
emit light.
PHOTODIODE
The photodiode is a semiconductor
which controls the current flow
according to the amount of light.LED (LIGHT EMITTING DIODE)
Upon current flow, these diodes emit
light without producing the heat of a
comparable light.
DISTRIBUTOR, IIA
Channels high-voltage current from
the ignition coil to the individual
spark plugs.METER, ANALOG
Current flow activates a magnetic
coil which causes a needle to move,
thereby providing a relative display
against a background calibration.
FUSEA thin metal strip which burns through
when too much current flows through it,
thereby stopping current flow and
protecting a circuit from damage.
FUSIBLE LINK
METER, DIGITAL
Current flow activates one or many
LED's, LCD's, or fluorescent
displays, which provide a relative or
digital display.
FUEL
FUSIBLE LINK
A heavy-gauge wire placed in high
amperage circuits which burns through on
overloads, thereby protecting the circuit.
The numbers indicate the crosssection
surface area of the wires.(for Medium Current Fuse)
(for High Current Fuse or
Fusible Link)MOTOR
A power unit which converts
electrical energy into mechanical
energy, especially rotary motion.
M

IG08R-01
B04085
IG-6
- IGNITIONIGNITION COIL
1809 Author
: Date
:
2004 LAND CRUISER (RM1071U)
REMOVAL
1. REMOVE V-BANK COVER
2. REMOVE INTAKE AIR CONNECTOR
3. DISCONNECT ENGINE WIRE FROM LH CYLINDER
HEAD COVER
Disconnect the 2 wire clamps and engine wire.
4. DISCONNECT IGNITION COIL (WITH IGNITER) CON-
NECTORS
5. REMOVE IGNITION COILS (WITH IGNITER) FROM
SPARK PLUGS
Remove the bolt, and pull out the ignition coil (with igniter). Re-
move the 8 ignition coils (with igniter).
Torque: 7.5 N´m (80 kgf´cm, 66 in.´lbf)

IG08P-03
- IGNITIONIGNITION SYSTEM
IG-1
1804 Author
: Date
:
2004 LAND CRUISER (RM1071U)
IGNITION SYSTEM
ON-VEHICLE INSPECTION
NOTICE:
ºColdº and ºHotº in these sentences express the tempera-
ture of the coils themselves. ºColdº is from -10°C (14°F) to
50°C (122°F) and ºHotº is from 50°C (122°F) to 100°C
(212°F).
1. INSPECT IGNITION COIL (WITH IGNITER) AND
SPARK TEST
Check that the spark occurs.
(1) Remove the ignition coils (with igniter) (See page
IG-6).
(2) Remove the spark plugs.
(3) Install the spark plugs to each ignition coil (with ig-
niter), and connect the ignition coil (with igniter) con-
nector.
(4) Disconnect the 8 injector connectors.
(5) Ground the spark plug.
(6) Check if spark occurs while engine is being
cranked.
NOTICE:
To prevent gasoline from being injected from injectors dur-
ing this test, crank the engine for no more than 5 - 10 se-
conds at time.

CHECK POWER SUPPLY TO IGNITION COIL (WITH
SENSOR (See step 3)
SPARK TEST
Replace the crankshaft position sensor.
CHECK RESISTANCE OF CAMSHAFT POSITION
1. Turn ignition switch to ON.
2. Check that there is battery voltage at ignition coil positive (+)
terminal.
CHECK CONNECTION OF IGNITION COIL
CONNECTOR
Resistance:Cold Hot
CHECK RESISTANCE OF CRANKSHAFT POSITION
Resistance:Cold Hot 1,630 - 2,740 W2,065 - 3.225 W
CHECK IGT SIGNAL FROM ECM
(See page DI-202)
REPAIR WIRING BETWEEN IGNITION COIL
AND ECM
Replace the camshaft position sensor. Connect securely.
Check wiring between ignition switch
to ignition coil (with igniter).
Check ECM (See page IN-36)
NO
OK
OK
OK
OKBAD
BAD
BAD
BAD
BAD
SENSOR (See step 4) IGNITER) CHANGE IT TO NORMAL IGNITION COIL (WITH
IGNITER) AND PERFORM SPARK TEST AGAIN
OKReplace the ignition coil (with igniter).
NO
OK
985 - 1,600 W1,265 - 1,890 W
IG-2
- IGNITIONIGNITION SYSTEM
1805 Author
: Date
:
2004 LAND CRUISER (RM1071U)
If the spark does not occur, do the test as follows:
(7) Using a 16 mm plug wrench, install the spark plugs.
Torque: 17.5 N´m (180 kgf´cm, 13 ft´lbf)
(8) Reinstall the ignition coils (with igniter) (See page
IG-6).
2. INSPECT SPARK PLUGS
NOTICE:

Never use a wire brush for cleaning.

Never attempt to adjust the electrode gap on used
spark plug.

Spark plug should be replaced every 100,000 km
(60,000 miles).
(a) Remove the ignition coils (with igniter) (See page
IG-6).